Demurrage and Detention Disputes: The 2026 FMC Rules Playbook

For most importers, demurrage and detention charges have always felt like a cost of doing business rather than a line item worth contesting. Invoices arrive from the carrier or terminal, the amounts are frustrating but usually paid, and the finance team moves on. That posture made sense when the rules governing these charges were vague and the billing party was whoever the carrier decided to bill. It no longer makes sense in 2026.

The Federal Maritime Commission's Demurrage and Detention Billing Requirements rule, in force since May 2024, requires ocean common carriers and marine terminal operators to include specific, defined information on every demurrage and detention invoice and to follow fixed timelines for issuing invoices and resolving disputes. An invoice that fails to meet those requirements is not a technicality. Under the rule, a non-compliant invoice does not create a payment obligation until it is corrected. That single fact turns invoice review from a bookkeeping task into a recovery program.

2026 adds a second layer of change. In September 2025, the D.C. Circuit ruled in World Shipping Council v. FMC that the Commission had inadequately justified the part of the rule restricting which party carriers and terminals could bill for demurrage and detention. The court vacated that provision, and on January 2, 2026 the FMC issued a final rule formally removing it from the regulation. The content, timing, and dispute provisions of the rule are unaffected and remain fully in force. What changed is that billing party assignment is now a contractual question again, not a regulatory guarantee, which means importers who have not addressed it directly in their carrier, NVOCC, and drayage agreements are exposed to being billed in ways the 2024 rule was originally designed to prevent.

This guide is written for importers running 10 or more containers monthly who want to convert this regulatory landscape into lower net demurrage and detention spend. It covers what the current rule requires, what the billing party vacatur actually changed, how to build a systematic invoice audit and dispute program, the operational tactics that prevent charges before they are ever billed, and the contract terms that matter now that the FMC is no longer dictating who gets the invoice. It assumes you already know what demurrage and detention are and are looking for the mechanics of reducing what you actually pay. For contract-level cost recovery beyond D&D specifically, the hidden freight contract costs guide covers the broader category of contract clauses worth auditing.

The FMC's rule sets a floor of required information on every demurrage and detention invoice. The requirement combines 13 data elements specified directly in the Ocean Shipping Reform Act with 7 additional elements the Commission added for clarity, for a total of 20 elements that a compliant invoice must include. In practice, these fall into three groups.

Timing and container information includes the container number or numbers covered by the charge, the port or ports of loading and discharge, the dates the container qualifies as available for pickup or return, the specific date range for which the charge applies, and the applicable last free day. If a carrier bills you for detention starting on a date before the container was actually available for pickup, or bases demurrage on an incorrect last free day, the invoice fails on this element alone.

Rate and calculation information includes the total amount due, the applicable per diem or per day rate, and enough detail about which tariff or service contract rate applies for the billed party to actually locate and verify it. A carrier cannot bill a flat total with no rate basis shown and expect the charge to be enforceable. This is the element most frequently missing or vague on invoices from smaller NVOCCs and some terminal operators, and it is one of the easiest to catch in a systematic audit because the rate reference should always be traceable to a specific published or contracted rate.

Dispute and contact information includes a specific contact for questions or disputes about the charge, not a generic billing inbox, along with clear notice of the billed party's right to dispute the invoice and the applicable timeline. Carriers and marine terminal operators must issue the invoice within 30 days of the last event giving rise to the charge, typically container pickup, return, or the end of the demurrage period. Once you receive a compliant invoice, you have 30 days to dispute it in writing, and the carrier then has 30 days from receipt of your dispute to respond substantively, either withdrawing the charge, reducing it, or providing a documented basis for upholding it.

Two practical points follow from this structure. First, an invoice issued more than 30 days after the triggering event is itself non-compliant and can be disputed on timing grounds regardless of whether the underlying charge is otherwise valid. Second, the 30-day dispute clock starts when you receive the invoice, not when someone gets around to reviewing it, so a queue of unreviewed D&D invoices sitting in an inbox is directly costing you dispute rights as the clock runs. Building a workflow that routes every D&D invoice to review within days of receipt, not weeks, is the single highest-leverage process change in this entire guide.

Before the WSC v. FMC decision, the rule specified which party a carrier or marine terminal operator could bill for demurrage and detention in different scenarios, generally limiting the pool to parties with a direct contractual or possessory relationship to the container, such as the consignee, the NVOCC that booked the space, or the trucker who picked up the box. The World Shipping Council challenged this provision, arguing the Commission had not adequately justified restricting carrier billing discretion, and the D.C. Circuit agreed. The court found the FMC's reasoning for the restriction inadequately explained and internally inconsistent, and it vacated that specific provision, section 541.4, while leaving the rest of the rule, invoice content, timing, and dispute procedures, fully intact. The FMC's January 2026 final rule formally implemented the removal.

What this means in practice is that carriers and marine terminal operators have regained discretion over who they choose to bill for demurrage and detention, within the bounds of their own tariffs and service contracts. For an importer who books through an NVOCC, this reopens a scenario the original rule was designed to close off: a carrier billing the beneficial cargo owner directly for detention even when the NVOCC held the booking and controlled the container movement, or a marine terminal operator billing whichever party is easiest to collect from rather than the party actually responsible for the delay.

The practical response is to stop relying on the regulation to define billing party assignment and start defining it explicitly in your own contracts. Three relationships need this language now. Your ocean carrier or NVOCC service contract should state explicitly who the carrier will bill for demurrage and who bears responsibility for detention once the container leaves the terminal, with clear language on where NVOCC responsibility ends and BCO responsibility begins. Your drayage contract should specify who is billed for chassis-related detention delays versus delays attributable to your own receiving operation, since drayage providers increasingly pass through detention charges they receive from carriers, and without contract language you have limited recourse to push back on which delays were actually within the trucker's control. Your customs brokerage and warehousing agreements, where relevant, should address responsibility for delays caused by documentation issues or receiving capacity, since those delays are frequently the root cause of detention charges that get billed upstream to the BCO by default.

If your current agreements are silent on billing party assignment, and most agreements signed before 2024 are, this is worth a focused amendment discussion at your next renewal rather than waiting for the full contract to come up for renegotiation. A carrier or NVOCC that resists specifying billing party terms in writing is signaling that ambiguity currently benefits them, which is itself useful information for your negotiation.

Most importers review demurrage and detention invoices reactively, checking amounts against expectations and paying what looks roughly right. A systematic audit program instead checks every invoice against the FMC's compliance requirements before it checks the amount, because a non-compliant invoice does not need to be paid regardless of whether the underlying charge would otherwise be valid.

The audit workflow that works at scale has four steps. First, run every incoming D&D invoice through a compliance checklist covering the 20 required data elements before anyone reviews the dollar amount. This can be a structured spreadsheet template or a rule set built into your freight audit software, but it needs to check for presence and internal consistency of each element, not just presence. A rate figure that appears on the invoice but does not match any rate in your service contract or the applicable tariff is functionally a missing element, because the billed party cannot verify it.

Second, cross-reference the dates and container events on the invoice against your own operational records: gate-in and gate-out timestamps from the terminal, appointment confirmations, and any documented delays outside your control. This is where most disputable charges are found. Common discrepancies include invoices calculating free time from an incorrect vessel discharge date, detention charges continuing to accrue after a container was actually returned empty, and demurrage billed for days when the terminal itself was closed or the port had no available appointments, none of which should count against your free time under most tariffs and service contracts.

Third, for every invoice with a compliance gap or a documented factual discrepancy, file a written dispute within the 30-day window, citing the specific deficiency and attaching supporting documentation. Generic disputes that simply state disagreement without citing the specific FMC element that is missing or the specific date discrepancy are weaker and slower to resolve than disputes that reference the exact regulatory basis. Track every dispute with its filing date and the carrier's 30-day response deadline in a shared log, not in individual email threads, so nothing falls through when volume is high during peak periods.

Fourth, treat unresolved disputes past the carrier's 30-day response deadline as an escalation trigger, not a dead end. A carrier that fails to respond within the required window has itself violated the rule's dispute resolution timeline, which strengthens your position if the matter proceeds further. For persistent non-compliance from a specific carrier or terminal operator across multiple shipments, a documented pattern is also the basis for a formal complaint to the FMC, which importers use more as a last-resort escalation than a routine tool, but the credible threat of it changes carrier behavior on repeat disputes.

Importers running this process systematically, rather than sporadically, typically find that a meaningful share of their D&D invoice volume has at least one valid basis for dispute, whether a compliance gap or a factual date discrepancy. The recovery rate on properly documented disputes is materially higher than on informal pushback, because carriers and terminal operators have their own compliance obligations under the rule and generally prefer to correct or withdraw a deficient invoice over risking a pattern of unresolved disputes that draws Commission attention.

Disputing invalid charges recovers money after the fact. Avoiding charges in the first place is worth more, because every dollar of demurrage or detention avoided is a dollar you never had to audit, dispute, or wait 60 days to resolve. The strongest D&D cost programs run avoidance and dispute processes in parallel, not as a sequence.

Appointment and pickup discipline is the highest-leverage avoidance lever for detention. Set an internal target of container pickup within 48 hours of availability notice on every import, and track exceptions with a named reason: chassis shortage, drayage capacity, receiving dock availability, or customs hold. If a specific reason recurs across multiple containers in a month, that is the actual bottleneck to fix, not a generalized capacity problem. For importers with predictable weekly import volume, booking recurring drayage appointments in advance with your trucking provider, rather than requesting appointments reactively after each container becomes available, measurably reduces the number of containers that sit past free time waiting for a truck slot.

Dual transactions, where a drayage provider drops an empty container and picks up a loaded one in the same terminal visit, or the reverse, reduce the number of terminal trips required per container cycle and directly shorten the window during which detention can accrue. Not all terminals or drayage providers support dual transactions on every move, but where available, they typically cut a full terminal visit out of the container cycle, which both lowers cost per move and reduces detention exposure on the return leg.

Empty return planning deserves its own attention because a large share of avoidable detention charges come from containers that were unloaded on time but returned late, not from pickup delays. Confirm empty return locations and hours before the container is even picked up, since return location restrictions change frequently at congested terminals and a container routed to a return location that is full or restricted on arrival generates detention through no fault of the unloading operation. Where your volume supports it, negotiate street turns with your carrier, reusing an empty container for an outbound load instead of returning it to the terminal at all, which eliminates the return leg's detention exposure entirely for that container.

Free time itself is a negotiated term, not a fixed constant, and importers with 10 or more containers monthly on a lane have real leverage to extend it. Standard free time on major trade lanes typically runs 4 to 5 calendar days for demurrage and detention combined, but carriers routinely offer extended free time, 7 to 10 days is achievable for importers with consistent volume and a clean payment history, as part of an annual service contract negotiation. This is a term worth raising explicitly during contract season rather than treating free time as fixed. The freight procurement contract season playbook covers the broader annual negotiation calendar this fits into.

Finally, during known congestion periods, whether seasonal peak, a port labor event, or a weather disruption, shift your planning assumptions ahead of time rather than reacting after containers start accruing charges. If your appointment data or your carrier's own advisories signal an extended dwell period at a specific terminal, extend your internal pickup target and pre-position drayage capacity accordingly. The cost of over-preparing for a congestion event that turns out to be minor is small compared to the detention exposure from being caught unprepared for one that is not.

With the FMC no longer dictating billing party assignment, the terms that used to be guaranteed by regulation now need to be secured through negotiation. Importers renewing ocean carrier, NVOCC, or drayage agreements in 2026 should treat this as a required agenda item, not an optional add-on, particularly for any relationship where the prior assumption was that the regulation itself provided sufficient protection.

Specific terms worth pushing for in carrier and NVOCC agreements: explicit billing party language stating who is invoiced for demurrage and who is invoiced for detention, with clear handoff points if responsibility shifts partway through the container's dwell (for example, from the NVOCC during the ocean leg to the BCO after pickup). A per diem rate cap or schedule attached to the contract, rather than defaulting to published tariff rates, which are typically higher than negotiated contract rates and are what you get billed under absent a specific agreement. Free time terms stated as a specific number of days in the contract, not a reference to "standard" free time, since standard free time varies by port and can change without notice. And a dispute escalation contact named in the contract itself, so your team has a direct line for disputes rather than routing through a general customer service queue that adds days to resolution time.

In drayage agreements, the key addition is a clear allocation of responsibility for detention caused by drayage-side delays, chassis unavailability, driver scheduling, or equipment breakdown, versus detention caused by your own receiving capacity or documentation delays. Without this allocation, drayage providers commonly pass through the full detention charge regardless of fault, and disputing that after the fact with your own drayage provider is a weaker position than having the allocation defined upfront. Ask your drayage provider directly what percentage of detention charges on your account over the past 12 months were attributable to chassis or driver availability issues on their side; a provider unwilling or unable to answer this is one you have limited data leverage over in a dispute.

For importers working through freight forwarders or 3PLs rather than contracting with carriers directly, confirm explicitly who holds dispute responsibility and who receives the FMC-required dispute contact information on your behalf. Some forwarder agreements handle D&D disputes as a value-added service; others leave the BCO to manage disputes independently even though the forwarder controlled the original booking. This distinction matters enormously for how much of this guide's audit and dispute workload falls on your team directly versus your ocean freight provider.

None of these terms are things carriers volunteer. They are negotiated additions that matter more now than they did under the pre-vacatur rule, and importers who raise them explicitly at renewal are in a stronger position than those who assume the regulatory framework still covers gaps it no longer covers.

Every dispute in the audit process described above depends on documentation that proves your version of events: when a container actually became available, when it was actually returned, and what prevented pickup or return within free time. Importers without systematic documentation capture find themselves disputing charges on the strength of an invoice review alone, which is weaker than disputing with terminal timestamps, appointment confirmations, and photographic evidence attached.

The documentation that matters most for D&D disputes includes terminal gate transaction records showing exact gate-in and gate-out times for every container move, which most port terminal operating systems make available through API or portal access and which should be pulled and archived for every container, not just ones already in dispute. Appointment system records showing when appointments were requested, confirmed, and if relevant, denied due to lack of availability, since a denied appointment during your free time window is strong evidence that the delay was not within your control. Photographic or video evidence of container condition at pickup and return, which matters less for demurrage and detention disputes specifically but is worth capturing as part of the same workflow since it supports related damage and chassis disputes. And a running log of any terminal closures, equipment shortages, or force majeure events communicated by the port or carrier during the relevant period, since these are frequently the basis for a free time extension that the carrier's own tariff already provides for but does not apply automatically.

Manually assembling this documentation for every disputed invoice is workable at low volume but breaks down once you are managing 20 or more D&D disputes monthly, which is common for importers running 15 or more containers a month through congested gateway ports. At that volume, the practical solution is a system that ingests terminal and appointment data automatically and flags containers approaching free time expiration before the charge accrues, not just after the invoice arrives. This shifts the workflow from dispute-after-the-fact to alert-before-the-charge, which is both cheaper to operate and more effective, since preventing a charge is always less work than disputing one.

Cubic's platform includes automated freight audit functionality that checks incoming demurrage and detention invoices against the FMC's required data elements and against your own gate and appointment records, flagging discrepancies for review before payment rather than after. For importers managing this process in spreadsheets today, the operational lift to formalize it is real but the return is direct: every invoice caught before payment is money that never left your account in the first place, compared to a dispute-and-recovery cycle that can take 60 or more days even when it succeeds.

Converting this guide into a working program follows a sequence that prioritizes stopping the bleeding on current invoices before building the longer-term contract and system changes.

Days 1-30: Audit baseline and process setup. Pull every demurrage and detention invoice from the past 90 days and run them through the 20-element compliance checklist described above. Quantify the share with at least one compliance gap and the total dollar value at stake, which becomes your baseline recovery opportunity and the business case for the rest of the program. Stand up a routing workflow so every new D&D invoice reaches a reviewer within 3 business days of receipt, protecting your 30-day dispute window. File disputes on any invoices from the past 90 days still within the dispute window.

Days 31-60: Contract review and operational fixes. Review your ocean carrier, NVOCC, and drayage agreements for billing party, free time, and per diem rate language, and flag every agreement silent on these points as a renewal priority. Identify your top three recurring causes of detention delay from the audit data, chassis, drayage capacity, receiving dock, or documentation, and assign an operational owner to fix the highest-volume one. Implement dual transaction and street turn options with your drayage provider wherever the terminal supports them.

Days 61-90: Documentation systems and negotiation. Set up automated capture of terminal gate transactions and appointment records for your highest-volume ports, either through your TMS, your forwarder's platform, or a dedicated tool. Bring the specific contract language identified in days 31-60 into your next carrier or drayage negotiation, using your audit data on dispute volume and delay causes as leverage. Set a recurring monthly cadence for reviewing D&D spend against the prior 90-day baseline to confirm the program is producing measurable reduction.

Importers who run this sequence consistently see the most impact on net D&D spend within the first two quarters, driven roughly equally by successful disputes on non-compliant invoices and by reduced charge volume from operational and contract fixes. The programs that stall are almost always the ones that treat this as a one-time cleanup rather than an ongoing discipline; carriers and terminal operators do not stay compliant indefinitely without sustained scrutiny, and free time and rate terms erode back toward standard tariff levels if they are not actively maintained at each contract renewal.

For a review of your current demurrage and detention exposure and a tailored assessment of where your program stands against the framework in this guide, reach out to Cubic's logistics team. We work with high-volume importers across the major US gateway ports and can typically identify the highest-value disputes and process gaps within a single invoice review session.